ICT Chapter 2: Hardware and Software

Pros of Cloud

- Can be accessed at any time -Do not have to be sitting a specific computer or organisation. -Allows synchronisation to a computer

Inkjet printer

- Cheapest of all printers-varies - Vary in price-'compatible' versions can be bought - Almost all can print in colour -Good quality-ink can show, smudges can happen

Pros and cons of off the shelf

- Cost lower as development cost spread to all customers. - Software may not be compatible with existing hardware - Used by thousands so bugs likely to be found and fixed. - Wide range of support

Backup

- Create a second copy of data and programs that are in storage. - Backup utility can be executed by the user, in which case backup takes place when user wants it to. - User can select which files to back up and where.

File copying

- Files can be copied using features within a OS's own interface. - Can be slow and limited options. - File copying utilities allow users to have more control on copying files. - Also possible to sync files across many storage locations or many systems, so when change made, made to all systems.

Plotter

- Slow speed-due to large area need to be covered - Most expensive type of printer - Running costs same as inkjet printers - Can print in colour -High quality if pens used even higher

Deleting

- Some files may be locked by OS - Deleting utilities can fix this problem by deleting locked files and folders. - When files deleted normally, data is still there but not visible to user. - Another function of deleting utilities is being able to delete files permanently. - Some deletion utilities will remove temporary files no longer needed by computer.

Dialogue interface

- Spoken word to communication with computer system. - Human says command, computer responds with further information. -

Mental models

- This is a persons understanding of how something works. - Different people = different ideas, assumptions. - User has own understanding fo how system and its interface works and will make own assumptions from experience. - More exp= easier to learn new interfaces. -If interfaces can be designed to be similar to users mental model, it will reduce amount of time needed to learn. -Interfaces should reflected preconceived ideas of majority of users. -Same task can be achieved in different ways, which fits with each user's mental model. For e.g: some prefer to click B for bold, some Ctrl+B. -Sometime its no better to follow users mental model cause it might be inefficient.

Web authoring:

- Used for creating and editing software.

Formatting

- When a disc is prepared for first time use, needs to be formatted. - Formatting is the process organising the tracks on the disc into sectors. - Each sector is where data will be stored. - Used disc can also be formatted in which all data will lose and the tracks prepared again as if new disc.

Data compression

- Will reduce the original size of files so that they use up less storage space. - Can be achieved on a file by file basis or for a set of files. - Slower to open the compressed file but smaller so takes up less storage and can be transferred from one place to another quickly.

Pros and cons of custom written

- Written for specific client- expensive - Takes long time to develop - Requirements of the client can be met precisely - Bugs likely to be found as its not been used before - Less likely to support.

ROM

- non volatile -Once written, it cannot be changed-permanent

Hard disk drive

-Acts as main secondary storage device for a computer -Data and programs are stored on HDD so can be accessed when needed. -external HDD's can also be used to back up data or transfer data to another computer. -Moving parts in HDD make it prone to damage

How does OS manage software?

-Allocating memory to software -Sending data and instructions to output devices -Responding to input devices when key is pressed -Opening and closing files on storage devices -Giving each running task a fair share of processor time -Sending error or status messages to apps or users -Dealing with logons and security

CLI

-Allows user to enter text commands to which the comsystem will respond. Response will be results in text.

Roles of different utility software

-Anti-virus: Deals with other threats such as adware and spyware as well as viruses. Has two main functions: Anti virus monitor that always searches for viruses and malware. Known as scanning the system. If anything is found user is informed and given option to remove it or ignore it. Disinfecting is the safest options as it completely removes the threat. Compromise is put affected area into quarantine.

Portable hard disk drive

-Can be connected to computer using USB or eSATA port -Can store a lot of data -Prone to damage

Pros and cons of GUI

-Complex GUIS need to a lot of memory to work -Simpler ones don't need that much. -Simple and can be used instead of CLI in small -systems such as embedded systems -Common to find web based GUIS for maintenance- devices like switches, printers. -GUIS easy to learn- commands rep by pictures. -Can be restrictive though for technical users who wanna do some next task.

OMR

-Detects mark made on multiple choice document. -Scanner like device used to detect mark -OMR cannot understand letters or words

OCR

-Device that allows characters on a document to be seen and understood by the computer. -Scanner combined with software-- ocr (recognition) -Pic of document analyses that turned into document so text can be searched or edited.

Laser printer

-Fastest of all printer - Expensive-twice cost of inkjet - Expensive toners but robust - Colour: most monochrome but colour available - Highest quality

Memory card

-Flash memory on a small card -Used in digital cameras, digital video cameras and mobile phones -Take very little space -Well suited to fitting into small device -Portable--convenient -Many different formats, most devices like SD and microSD.

Dot matrix printer

-Impact printer, operation is very noisy. -Very slow compared -Expensive now - Rare for colour -Poor quality -Very robust - Poor quality-bitmap

Video editing software

-Importing or capturing raw video -Clipping the beginning and end of a video -Adding back up music -Altering video speed

Magnetic ink character reader

-Ink used to print numbers bottom of checks -Uses iron oxide easily detected when using MICR -MICR more accurate than OCR

Storage devices

-Main purpose of storage device to store data or software that can be used a computer. -Known as secondary storage- non volatile

Advantages of RAM

-More RAM available to the computer, the more data and programs can be used at the same time -Useful for multitasking programs

HDD

-Most common form of Secsor due to cost -In 2015, HDD could store up to 8 TB =Drive includes read-write head which sits at the end of a access arm and magnetises sectors on the disk. Usually more than one platter therefore several read write heads Data stored on a hard disk is non-volatile Hard discs can be internally connected to computer using SATA.

Device drivers

-OS needs device drivers to deal with certain makes, models of hardware. A device driver is the software that comes with an external hardware part and then sends customised instruction to that part.

Bluray disk:

-Optical storage medium -Same size as CD and DVD - Store HD video -A single layer blu ray disc can store 25 GB of data, dual layer 50GB -Compared to DVD which can store 4.7 GB` of data and CD can 700MB -Uses lasers to read data -Basic blu ray disc can read at 4.5 MB/s -Much slower than a HDD but cheaper -Standard blu ray disc is read only

Application software

-Programs that are meant for productivity or to carry out a task for the user. -Examples: word processor, games, web browser

Gesture based interface

-Recognises human motion, includes tracking eyes and lips, monitoring whole body movement, hand signals. -Many applications of GBI inc. gaming, such as Wii, move with their hands using controller, Xbox --Kinect able to track whole body movement with no devices. Many computer system such as mobile devices, starting to include hand gestures. Swipe of the hand may close a program, pinching fingers together zoom in or out. Avoid greasy screens and help with infection control in hospitals. Gestures can be essential form of interaction for disabled A disabled person with no control from neck downwards could control a computer system with their eyes. Biggest problem with GBI is accuracy Needs to accurately understand users movements. Tracking certain fingers, arms, eyes, needs highly accurate cameras or sensors.

SDD

-SDD is another secondary storage device that is non volatile -No moving parts and data is stored onto flash memory -data can be stored anywhere on the flash memory and access speed will not be affected. -Non magnetic so not susceptible to damage from magnetic fields -In 2015, SSD could store up to 8 TB -Far more expensive than HDDs and more common in lower capacities. -2-3 faster than HDD -Used in high performance computers. -SSDs also require a lot less power than HDD's and so are preferred in laptop and tablet computers.

Pen drive

-Small data storage device -Stores data on flash memory -USB interface means flash drive is recognised by --all computers- easy to transport data -Fast memory -Limiting factor, speed of USB port -Safe to transport

Utility software

-Software that performs some sort of maintenance on the system. -Doesn't include OS, but may come preinstalled.

Cons of dialogue interface

-Sometimes computer system doesn't always get it due to accents, different voices, background voices. -Also requires for the user to know what commands are understood by the system cause then the system won't know how to respond. -Some dialogue interfaces will give prompts telling users what options they can choose. -They are not intelligent enough to understand any type of request for example: How long are my feet?

Cons of Cloud

-Takes longer to access the data as access times are limited by bandwidth available to hosting company. -Costly to store large amounts of data on cloud storage.

System software

-This is programs that are designed to maintain or operate the computer system.

Optical

-Three main types of optical storage: `, DVD, Bluray -Optical storage popular due to low cost of each disc, that read only versions exist and low cost of posting them. -suitable for backups and archives. -File can be accessed directly rather than having to read through whole tape-Quicker to restore single file from optical disc back up-suitable for archived data because files can be found quickly. -Capacity of optical discs much less than tapes-not suitable for large backup.

Interpreters

-Translate a program written in high level programming code into machine code one line at a time. -Can be less efficient than compiler- takes longer to translate and statements within programming loops have to be analysed each time. -Often used to translate macros or application based script languages -This can be useful when a doc needs to opened on many OS's. -Interpreters are also used when testing programs so that parts of the program can be executed without compiling it all.

Photo editing software

-Type of GM software- focused on editing photos Features: -Cropping -Removing red eye -Resizing canvas -Sharpening a photo -Adjusting contrast or brightness -Photo editing software require a lot of RAM and hard operations takes up many processing time.

Magnetic tape drive

-Used for backing up and archiving data -Stored one item after another. -Low cost and high capacity- ideal for back up -Takes a while to find data required cause tape has to be wound to exact position where data is stored--Makes it unsuitable for everyday use-takes long Backups and archives not for everyday use If whole secsor of computer needs to be restored, can be done by reading the tape sequentially. Tapes for ideal for back up whole secsor for computer cause they can hold bare TB' of data.

Database management systems

-Used for viewing and editing data within database -A database is structured collection of data in form of tables that are related to each other.

Scanner

-Used to capture 2D documents in form of an image. -Flatbed scanners can capture full colour image -If image has bare text you can use OCR. -Some fb scanners have ADF allows bare docs scanned at once.

Barcode reader

-Used to detect width of lines and gaps that form a barcode. -Barcode scanner usually has own circuitry so it can send letters numbers to computer straight

Advantages and cons of CLI

-Uses very little memory so useful in old systems or for maintenance for very small systems. -Useful also for technical users who need to do bare hard operations that user friendly interface cannot give. -Cons: Difficult to learn (remembering all of commands), errors easy to make.

Storage devices reasons:

-When creating a document user would wanna make change to document -User might want another guy to edit or read document. -Archive purposes -When using a database, each new record will be saved to the database in secstor. -User might wanna back up data so spare copy is available.

Uses of word processing software

-Writing a letter -Producing a report -Producing coursework -Creating a menu -Mail merging -Features of the software: -Tables -Headers, footers -Fonts -Alignment

Off the shelf

-general purpose software available to large market.

Custom written

-software written especially to meet requirements of client.

Spreadsheet software

-used mainly for calculations and modelling. -Often financial and statistical info. -Input-Process-Output cycle -When input changes, so does output data. -Allows users to experiment with values and ask 'What-if?' questions

Cloud

-where computing services are hosted over the internet and not in the same physical location as the computer being used. -Data is stored on banks of servers that are accessed remotely. -hosting company takes all responsibility for the data

Arithmetic Logic Unit

ALU does calculations and logical operations

Uses of plotter

Arc drawings, large maps, canvas prints and signs.

CPU

Brain of computer, Carries out calculations, instructions and processes data, contains ALU and CU

Advantage of device drivers

By using device drivers, software applications can just use commands like print to the OS, not needing to know make, model.

CU

CU runs fetch-execute cycle which fetches instructions from memory and execute them.

Communications software

Can cover a range of tasks like instant messaging, audio, video conferencing, email.

Motherboard

Contains main part of computer system, inc. USB, network port, graphics card

Control and measuring software

Control software used for controlling devices not part of computer system Measuring software used to measure values in the real world.

DBMS

DBMS features: -Data entry screens -Filters and queries -Reports -Graphs for analysation -Relationships

Blu ray disk v CD v DVD storage

DVD which can store 4.7 GB` of data and CD can 700MB

Non-Volatile

Data is not lost when turned off

Input device

Device that allows data to be entered onto computer system

Examples of web authoring

Dreamware is an example Can be bare hard to use. www.wix.com helps people with little experience of websites. Web authoring software gives most flexibility and websites can be configured exactly as required. Features Common navigations tabs Preview of web pages Adding basic HTML features like tables, headings. Interactive features

Keyboard

Ergonomic keyboards are available to provide more comfort and prevent RSI

Graphics manipulation software

Features for bitmap and graphics: - Drawing shapes -Changing canvas size -Adding layers -Adding text to image Features for only bit: -Filling area with colour -Moving part of image -Resizing part of image -Erasing parts of image Features for only vector: -Filling a shape with colour -Aligning objects -Moving a shapes -Resizing a shape

GUI

Found on desktop computers, tablet computers, phones, TV's, etc. Include: Windows- An area of screen for specific task. Icons: An image used to represent a program, file task. Selected to open. Menu: Words on the screen which represent list of options- can be expanded to sub-menus. Pointers- Represents movement from pointing device such as mouse.

Linkers

Function of a linker is to combine the object files together to form a single executable file.

Graphics card

Graphics card: - Connected to motherboard -Purpose is to generate the signals needed to display output image from computer -Includes a variety of options for output.

Uses of dot matrix

Invoices, receipts, data logging.

Uses of laser printer

Letters, bulk printing, general office and home printing.

Monitor

Monitor: -Enables user to visualise the output. -Connected to computer using one of the ports on a graphic card. -Most are flat screens which minimize amount of desk space used.

Uses of control

Motors Lights Speakers Heating

What is hardware categorised into?

Output, input, storage devices

Utilities

Part of system software, designed to perform functions which maintain computer system

Uses of inkjet printer

Photographs, charts, small maps, general office and home printing.

Advantages of dialogue interface

Popular with mobile devices, car system -Big pro, hands-free, makes them useful in cars or when holding a phone. -Can be spoken quicker than typed -No need for physical interface- so suitable for system like home automation.

Uses of monitor

Pressure Moisture temperature Wind speed pH

Sound card

Purpose is to generate signals needed to output sound from the computer to a speaker or set of speakers. -Often part of motherboard -If higher quality sound is needed, then separate sound card needed.

Operating system

Software that operates the computer hardware It manages any communication between both hardware and app software

Solid state drive

Storage device that typically uses flash memory to store data, instructions, and information. -Faster than HDD - More expensive -Needs less power than HDD - Storing OS and programs that are used most on a SSD not HDD will significantly improve computer performance.

RAM

Store active programs and data - Volatile

Compilers

Translates program written in high level programming code into machine code that computer can understand. File that has machine code i known as executable file or object file. Original high level programming language file is known as source file. When program is compiled, whole source code is translated into the executable file at once then distributed. As it is in executable format, can only be run on OS for which compiler has translated it.

What happens when RAM is full?

When RAM becomes full, inactive programs or data removed to make space for new programs If RAM is full and there's no programs to remove, then secondary storage known as virtual memory(e.g SSD or HDD) is used to expand amount of memory available to CPU.

Output device

a device used to communicate data or information from a computer system.

Storage device

a device used to store data onto storage media.

User interface

boundary between user and computer system

Volatile

data is lost when turned off

Device

hardware component of a system consisting of electronic components

Hardware

physical component of a system